Title: Gaia in Technicolor: Mapping Stellar Variability Through H-R Diagram Motions

Abstract: Most people think of the famous H-R diagram in stellar astrophysics as being essentially static over human lifetimes, changing only on timescales of millions or billions of years. However, some pulsating stars and eclipsing binaries exhibit photometric and color variations strong enough that their positions in the H-R diagram actually oscillate on much shorter timescales than their evolutionary timescales. The European Space Agency’s Gaia spacecraft makes the detection of these motions possible for millions of stars for the first time. By combining photometry from its G (green), BP (blue), and RP (red) filters, we can track individual stars’ positions in the H-R diagram across 50-100 different epochs throughout the lifetime of the Gaia mission. Here we present results showing that we can not only detect H-R diagram motions in millions of objects but also use the patterns of these motions to discover and classify new pulsators and binaries. In some cases, this approach has revealed previously unknown types of variables.